Rotary compressor or motor



Jan. 16, 1945. R. BECKMAN ROTARY COMPRESSOR OR MOTOR Original Filed Oct. 7, 1941 tor the entire Patented Jan. s, 1945 UNl'I' E'D STATES PATENT OFFI CE 1 I 7 permit com ii ri zza on Moron Richard Beckman, New York, N. Y.

(lrlginal' application October. 1,1941, Serial No.

413,945. I Divided and this application November .13, 1942, Serlal'No. 465,422

This invention relates to devices acting as com pressors or air or other elastic fluid, which devices are also capable of use as motors'when the -operation is reversed, namely compressed fluid is supplied thereto and mechanical force taken therefrom. I

.It is an object ofthe invention to provide an improved 'slidingvane-rotor for a compressor (or motor) 1 I .A further object of the invention is to provide an improved construction and relationship of sliding vanes in the rotor of a-compressor (or motor) whereby the'wear on thevvanes is reduced and their free and proper operation promoted.

Other and ancillary objects will appear hereinafter.

of the invention This application is adivisi'on of my prior ap- .metric channels, one pair I23' accommodating the plurigersof'a' pair of diametrically opposite vanes, and the other pair of channels I24, at

right anglesto the other pair, accommodating I the other pairs of plungers oi the diametrically plication Serial No. 413,945, filed October 1, 1941. I

, In the accompanying drawing which illustrates theinvention- I I Fig. 1 is an axial section of a single stage compressor' embodying the invention;

Fig. 2 is a section-on the line I2-I2 Fig. 1; Fig. 3 is a section on theline II-Ilof 1;

. 1 Fig. 4 is an enlarged section, partly broken away, on the line I4-I4 of Fig. 1;

Fig. 5 is an enlarged, fragmentary section on the line I5-I5 of Fig.2; I

Fig.6 is an end elevation of the apparatus of Figs. 1 to'4; Fig. 'l is a vector diagram showing the direction of the; pressure component of the blade structures against the rotor; and 1 the rotor body'of Fig. 8 is a vector diagram showing the angle -o1'.. application of force between the blade and;

the rotor body.

, Referring to the draw ng, Figs. 1 to s inclusive,

the single stage air compressor therein shown comprises a generally'cylindrical outer casing 81 having a circumferential chamber 88 for a cooling fluid having theintake "and" the discharge 90. .The inner surface of the casing'" forms.

the circular wall or a compression chamber,.the: ends of which are closed by the end heads SI and I2. Within the chamber is the eccentrlcally' mounted rotor having the cylindrical body poropposed vanes. The plunger channels ar d plungers therein of one pair of vanes are longitudinallydisplaced from the plunger and plunger channels of the other pair of vanes so that they may operate without interference- The plungers for one vane reciprocate in the plunger channels for one pair of vanes adjacent the ends atone side of the rotor body, while the plungers of the 25 other vane of the pair reciprocate in those plunger channelsat the ends thereof on the diametrically opposite side of said body. Between the plungers in each of said diametric channels are interposed springswhieh force the plungers and vanes radially outwardly toward the circumferential wall of the compression chamber. The rotor body has a centraljlubricating duct I25 .which extends from one end of the body to the other communicating with the vane plunger channels and the .ball bearings for the rotor.

' Lubricant may be supplied through an inlet I26 and the lubrication supplied to the vane plunger channels will permeate therethrough to the surfaces of the vanes and the interior wall of the compression chamber whereby all of the parts.

. 'will be adequately lubricated.

. The plungers operating at opposite ends'ofthe same diametric' channel in the rotor body and respectively fixed to opposite vanes of'aipair, are placed in such engagement with each other that they are rigidly held in line and form practically tion, which is in sealing engagement with the" 3 top of the compression chamber between the air intake port 84 and the outlet port". 90 apart, are slots 98, 81, 98 and 99 in'the cylindrical body,

- in which slots radially slide the flat vanes IOIL, IIII, I02 and I03. Such vanes or blades exten d length 01' the body portion or the rotor and at their ends form a sealed sliding con- 'nection with the rotor and heads Ill and! 'a single continuous structure so iaras any relative lateral displacement is concerned; butthey -move with relation to each other longitudinally.

so as to permit relative radial movement of the diametrically opposite vanes of a pair as is ,neces- 'sary' during the operation-of the apparatus.

It will be noticed from' Fig. 3 that horizontal vanes are closer-together as regards radial extent, than the vertical vanes and hence the vanes other is illustrated in Fig. 4 wherein one plunger III) to which is fixed the vane III sliding in one end of a diametric channel [I2 of the rotor body has its inner end I I3 reduced in diameter and telescoping with a close fit within the socket I formed in the end of the plunger H5 secured to the diametrically opposite vane II6. Between the shoulders III and H8 on these diametrically opposite plungers is inserted a spring II9 which forces the plunger outwardly. Within the reduced plunger portion [I3 is a bore I20 which at one end opens into the socket Ill and at the other end has a duct I2I connecting the bore with the bearing surface between the plunger and the rotor body. Also the socket Ill connects by means of a duct I22 with the bearing surface between the plunger H5 and the rotor body. Intermediate the ends of the reduced portion H3 and continually in connection with the central duct I25 extending centrally from one end to the other of the rotor as above referred to, is a duct I24. As the plungers separate, oil will be sucked from the duct I23 into the bore I20, and when the vane plungers are moved closer together the lubricant will be obliged to be expelled sufiiciently to permit the plungers to move toward each other as the lubricant is non-compressible and would prevent the movement of the vanes toward each other when necessary unless there were relief. While the channels I20 and I22 provide passage of sufllcient of the lubricant for lubricating purposes, the close clearances to which these ducts lead do not provide passage for a sufllcient amount of lubricant to decrease that between the opposed plungers so as to permit their necessary movement. Such relief, however, is provided by the vent I24 which is continually open to the duct I23. When the plungers are moved away from each other oil is sucked in through the duct I24 and when the plungers are moved toward each other a suflicient amount of oil may be forced through the ducts I20 and I22 for lubrication, but in any event the oil is vented through the duct I24 so that there is no undue restriction upon the inward relative move ment of the plungers.

This relative cooperation of opposing plungers, it will be seen, makes the plungers substantially one continuous structure so far as relative lateral movement or bending is'concerned, but relative diametrical movement is permitted so that the vanes may properly adjust themselves to their different angular positions in the compression chamber. This rendering of the vane plungers substantially a. single structure (except for the relative longitudinal movement referred to) is of reat importance. There is a certain amount of clearance between the vanes and plungerson the one hand and. the slots and channels in which they slide on the other. When, therefore, the tip of the vane encounters the inner surface of the compression chamber, the outer end of the vane is forced rearwardly and the vane comes against the corner of the slot where the vane emerges from the rotor body, the vane and its plungers, being tilted backwardly with relation to the rotor body. This tilting depends upon the clearancebetween the vanes and ass-mac their plungers on the one hand and the rotor body on the other, and upon the length of the plunger within the rotor body.

It will be seen'that with the clearance referred to fixed, as it is by other factors, the amount of tilting is dependent upon the length of the plunger within the rotor body. With each of the plungers separate and extending only a. fraction of the way through the rotor body, the length of the plunger within the body is so relatively short that the tilting is considerable especially when it is in its outermost position. This tilting of the vane causes it to assume a position with relation to the slot edge on the body portion such that instead of the vane bearing against the flat side of the slot it is at an angle thereto and bears heavily against the corner referred to. This results in undue wear of the vanes and what is more serious impedes their free operation in the operation of the apparatus.

By rendering the opposing plungers practically continuous, except for the relative longitudinal movement as referred as, the effective length of each plunger, as regards the tilting referred to, is greatly increased being equal to the entire diameter of the body portion. The clearances remaining. the same, which they do because of the other factors determining them, this greatly increased length of the effective plunger length within the rotor body will result in a great reduction and in fact a practical. elimination, of

the tilting of the plungers and vanes with consequent elimination of the wearing effect of the corners of the slots in the body upon the vanes. This will result in greatly increased durability I of the apparatus and also will insure no interfeience with the free operation of the vanes during the operation of the apparatus.

The advantage of the eiiectively long plunger over the individually shorter plunger is graphically illustrated in Figs. '7 and 8, Fi 8 representing conditions with the shorter plunger and Fig. 7 those of the long plunger. Thus in the figures referred to if a (constant) represents the width of the slot in which the vane slides, b (Fig. 8) represents the extent of the short plunger within the rotor body and the angular position of the driving side of the rotor slot with relation to the width, then the angle at which the vane encounters the outer corner of the drivin side of the slot will be represented by the angle 0. With the effective length of the plunger within the body being increased to the length d as shown in Fig. 7, the .angle 0 will be reduced to angle e, which is much reduced, and the vane is much more nearly parallel to the driving side of the rotor slot so that the digging or wearing effect of the outer corner of the slot upon the side of the vane is much reduced if not entirely eliminated.

While the invention has been illustrated in what is considered its best application it may have other embodiments without departing from its spirit and is not, therefore, limited to the structure shown in the drawing.

What I claim is:

1. In apparatus of the character described, the combination with a casing surrounding a pressure chamber and end heads therefor, of an eccentrically mounted rotor in said casing comprising radially reciprocating vanes and a body having diametric channels, plungers secured to diametrically opposite vanes reciprocating in opposite ends of the channels, and a connection bemovement but preventing relative lateral move- .ametrically opposite vanes reciprocating in opment of the last mentioned plungers one of the pos'ite ends of the channels, and a connection belast mentioned plungers having a reduced end tween plungers'reciprocatinginthe same diametportion forming a shoulder on the plunger and ric channel permitting relative longitudinal movethe other of the last mentioned plungers having 5 ment but, preventing relative lateral movement a recess into which the said reduced end portion of the last mentioned plunge s, e Of the last telescopically fits, a space being formed between mentioned plungers having a reduced end portion the said shoulder on one plunger and the end of forming a shoulder on the plunger and the other its diametrically opposite plunger, a vent in the of the last mentioned plungers having a recess wall of said recess,said reduced end plunger hav- 0 into which the said reduced end portion teleing a chamber communicating with said recess scopically fits, a space being formed between the and having vents in the wall of said chamber, one said shoulder on one plunger and the end of its in said reduced-end portion communicating with diametrically opposite plunger, a lateral vent in said space and one radially outward of said shoulthe wall of said recess beyond the end of said reder, said rotor having a longitudinal lubricating 15 duced portion in its innermost position, said reduct communicating with said space and a spring duced end plunger having a chamber communiin said space and bearing against said shoulder eating with said recess and having vents in the on one plunger and the end of its diametrically wall of said chamber, one in said reduced end opposite plunger. portion communicating with said space and one 2. In apparatus of the character described, the 20 radially outward of said shoulder, said rotor havcombination with a casing surrounding a presing a longitudinal lubricating duct communicatsure chamber and end head therefor, of an ecing with said space, and a spring in said space centrjcally mounted rotor in said casing comprisand bearing-against said shoulder on one plunger ing radially reciprocating vanes and a body havand the end of its diametrically opposite plunger. ing diametric channels, plungerssecured to di- 25 RICHARD BECKMAN. 

